Wireless communication systems typically include a base transceiver station (BTS) that provides service to one or more mobile stations within the coverage area of the BTS. The BTS may include a radio antenna system having one or more antennas mounted on a tower. The antennas may transmit downlink signals to and/or receive uplink signals from one or more mobile stations serviced by the BTS. Further, the radio antenna system may also include a tower-top low-noise amplifier assembly (TTLNA) and a feedline system (collectively, a receive signal path), which connects the base station located at the bottom of the tower to various components located at the top of the tower, such as the TTLNA.
It is standard practice to initialize the TTLNA in receive mode. Once the TTLNA has been initialized, the TTLNA will typically operate in either receive mode or in transmit mode. In receive mode, the TTLNA operates to receive signals from the antenna. The TTLNA passes the received signals through a sensitive microwave low noise amplifier (LNA) to amplify the signals. The amplified signals are then sent to the base station via the feedline system. In transmit mode, the TTLNA receives powerful transmit signals from the base station. In this mode, the LNA is bypassed and the powerful transmit signals from the base station are sent to the antenna.
According to current practice, the TTLNA relies on a relatively simple on-off signaling scheme to switch between receive mode and transmit mode. In this signaling scheme, the presence of a control signal causes the TTLNA to switch into transmit mode. And the absence of a signal causes the TTLNA to switch to its default resting state (i.e., receive mode).